CVE-2026-31457 — MEDIUM (5.5)

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs: check contexts->nr in repeat_call_fn damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(), damon_sysfs_upd_schemes_stats(), and damon_sysfs_upd_schemes_effective_quotas() without checking contexts->nr. If nr_contexts is set to 0 via sysfs while DAMON is running, these functions dereference contexts_arr[0] and cause a NULL pointer dereference. Add the missing check. For example, the issue can be reproduced using DAMON sysfs interface and DAMON user-space tool (damo) [1] like below. $ sudo damo start --refresh_interval 1s $ echo 0 | sudo tee \ /sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts

CVSS Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Affected Products

Vendor	Product	Versions
Linux	Linux Kernel	>= 6.17, < 6.18.21

Related Weaknesses (CWE)

CWE-476

References

FAQ

What is CVE-2026-31457?

CVE-2026-31457 is a vulnerability with a CVSS score of 5.5 (MEDIUM). In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs: check contexts->nr in repeat_call_fn damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(), damon_s...

How severe is CVE-2026-31457?

CVE-2026-31457 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-31457?

Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.